Most serious athletes will tell you that the competitive drive to win can be fierce. Besides the satisfaction of personal accomplishment, athletes often pursue dreams of winning a medal for their country or securing a spot on a professional team. In such an environment, the use of performance-enhancing drugs has become increasingly common.

But using performance-enhancing drugs — aka, doping — isn't without risks. Take the time to learn about the potential benefits, the health risks and the many unknowns regarding so-called performance-enhancing drugs such as anabolic steroids, androstenedione, human growth hormone, erythropoietin, diuretics, creatine and stimulants. You may decide that the benefits aren't worth the risks.

Anabolic steroids

What are they?

Some athletes take a form of steroids — known as anabolic-androgen steroids or just anabolic steroids — to increase their muscle mass and strength. The main anabolic steroid hormone produced by your body is testosterone.

Testosterone has two main effects on your body:

Anabolic effects promote muscle building.

Androgenic effects are responsible for male traits, such as facial hair and a deeper voice.

Some athletes take straight testosterone to boost their performance. Frequently, the anabolic steroids that athletes use are synthetic modifications of testosterone.

These hormones have approved medical uses, though improving athletic performance is not one of them. They can be taken as pills, injections or topical treatments.

Why are these drugs so appealing to athletes? Besides making muscles bigger, anabolic steroids may help athletes recover from a hard workout more quickly by reducing the muscle damage that occurs during the session. This enables athletes to work out harder and more frequently without overtraining. In addition, some athletes may like the aggressive feelings they get when they take the drugs.

Designer steroids

A particularly dangerous class of anabolic steroids are the so-called designer drugs — synthetic steroids that have been illicitly created to be undetectable by current drug tests. They are made specifically for athletes and have no approved medical use. Because of this, they haven't been tested or approved by the Food and Drug Administration (FDA) and represent a particular health threat to athletes.

Risks

Many athletes take anabolic steroids at doses that are much higher than those prescribed for medical reasons, and most of what is known about the drugs' effects on athletes comes from observing users.

It is impossible for researchers to design studies that would accurately test the effects of large doses of steroids on athletes, because giving participants such high doses would be unethical. This means that the effects of taking anabolic steroids at very high doses haven't been well-studied.

Anabolic steroids come with serious physical side effects as well. Men may develop:

Infections or diseases such as HIV or hepatitis if you're injecting the drugs

Inhibited growth and development, and risk of future health problems in teenagers

Taking anabolic-androgenic steroids to enhance athletic performance, besides being prohibited by most sports organizations, is illegal. In the past 20 years, more effective law enforcement in the United States has pushed much of the illegal steroid industry into the black market.

This poses additional health risks because the drugs are either made in other countries and smuggled in or made in clandestine labs in the United States. Either way, they aren't subject to government safety standards and could be impure or mislabeled.

Androstenedione

What is it?

Androstenedione (andro) is a hormone produced by the adrenal glands, ovaries and testes. It's a hormone that's normally converted to testosterone and estradiol in both men and women. Andro is available legally only in prescription form and is a controlled substance.

Manufacturers and bodybuilding magazines tout its ability to allow athletes to train harder and recover more quickly. However, its use as a performance-enhancing drug is illegal in the United States.

Scientific studies that refute these claims show that supplemental androstenedione doesn't increase testosterone and that your muscles don't get stronger with andro use.

Risks

Side effects of andro in men include:

Acne

Diminished sperm production

Shrinking of the testicles

Enlargement of the breasts

In women, side effects include:

Acne

Masculinization, such as deepening of the voice and male-pattern baldness

In both men and women, andro can decrease HDL cholesterol (the "good" cholesterol), which puts you at greater risk of heart attack and stroke.

Human growth hormone

What is it?

Human growth hormone, also known as gonadotropin, is a hormone that has an anabolic effect. Athletes take it to improve muscle mass and performance. However, it hasn't been shown conclusively to improve either strength or endurance. It is available only by prescription and is administered by injection.

Risks

Adverse effects related to human growth hormone range in severity and may include:

Joint pain

Muscle weakness

Fluid retention

Vision problems

Carpal tunnel syndrome

Impaired glucose regulation

Enlarged heart (cardiomegaly)

High cholesterol (hyperlipidemia)

Diabetes

High blood pressure (hypertension)

Erythropoietin

What is it?

Erythropoietin is a type of hormone used to treat anemia in people with severe kidney disease. It increases production of red blood cells and hemoglobin, resulting in improved movement of oxygen to the muscles. Epoetin, a synthetic form of erythropoietin, is commonly used by endurance athletes.

Risks

Erythropoietin use among competitive cyclists was common in the 1990s and allegedly contributed to at least 18 deaths. Inappropriate use of erythropoietin may increase the risk of thrombotic events, such as stroke, heart attack and pulmonary embolism.

Legal Conditions and Terms

Reprint Permissions

A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.org," "Mayo Clinic Healthy Living," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research.